On 25 February 1984 Masendych was consecrated by BishopSerapion (Fadeyev) of Vladimir and Suzdal, as a hieromonk.
In 1985 hieromonk Anthony was invited by Archbishop Gedeon (Dokukin) of Novosibirsk and Barnaul, to become a parson of church of Demetrius of Thessaloniki in a town of Aleysk.
In 1990 along with Metropolitan Gedeon (Dokukin), Antoniy moved to the Diocese of Stavropol and Baku where he became a dean over the Christian Orthodox parishes of Azerbaijan and a parson of the Baku Nativity of Mary church in rank of archimandrite.
In July 1991 he was appointed as a chairman of the Church department of foreign relations receiving a title of Archbishop of Kyiv.
Following consultations with government officials, in June 1992 Metropolitan Anthony finally agreed to unification with the Ukrainian Orthodox Church which was in crisis due to unsanctioned assembly of bishops and election of new primate from outside of the church.